Image sensors are used in cameras and other imaging devices to capture images. For example, light entering through an aperture at one end of the imaging device is directed to an image sensor by a beam shaping system (e.g., one or more passive optical elements such as lenses). The image sensors include pixels that generate signals in response to sensing received light. Commonly used image sensors include CCD (charge-coupled device) image sensors and CMOS (complementary metal-oxide-semiconductor) sensors.
Some image sensors include high-resolution primary imagers, as well as secondary imagers that can be used to provide depth information. Various advantages can be obtained by providing the primary and secondary cameras with a small foot print (e.g., both may be positioned on the same semiconductor chip (i.e., on the same sensor)). On the other hand, fabricating such modules with an overall small footprint while at the same time providing the desired optical characteristics can present a range of technical challenges.